sys/arch/macppc/dev/zs_kgdb.c

   1 /*      $NetBSD: zs_kgdb.c,v 1.13 2009/03/18 17:06:45 cegger Exp $      */
   2
   3 /*-
   4  * Copyright (c) 1996 The NetBSD Foundation, Inc.
   5  * All rights reserved.
   6  *
   7  * This code is derived from software contributed to The NetBSD Foundation
   8  * by Gordon W. Ross.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  29  * POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32 /*
  33  * Hooks for kgdb when attached via the z8530 driver
  34  *
  35  * To use this, build a kernel with: option KGDB, and
  36  * boot that kernel with "-d".  (The kernel will call
  37  * zs_kgdb_init, kgdb_connect.)  When the console prints
  38  * "kgdb waiting..." you run "gdb -k kernel" and do:
  39  *   (gdb) set remotebaud 19200
  40  *   (gdb) target remote /dev/ttyb
  41  */
  42
  43 #include <sys/cdefs.h>
  44 __KERNEL_RCSID(0, "$NetBSD: zs_kgdb.c,v 1.13 2009/03/18 17:06:45 cegger Exp $");
  45
  46 #include <sys/param.h>
  47 #include <sys/systm.h>
  48 #include <sys/proc.h>
  49 #include <sys/device.h>
  50 #include <sys/conf.h>
  51 #include <sys/ioctl.h>
  52 #include <sys/kernel.h>
  53 #include <sys/syslog.h>
  54 #include <sys/kgdb.h>
  55
  56 #include <dev/ofw/openfirm.h>
  57 #include <dev/ic/z8530reg.h>
  58 #include <machine/z8530var.h>
  59
  60 static void zs_setparam(struct zs_chanstate *, int, int);
  61 static void zskgdb(struct zs_chanstate *);
  62
  63 struct zsops zsops_kgdb;
  64
  65 static u_char zs_kgdb_regs[16] = {
  66         0,      /* 0: CMD (reset, etc.) */
  67         0,      /* 1: ~(ZSWR1_RIE | ZSWR1_TIE | ZSWR1_SIE) */
  68         0,      /* IVECT */
  69         ZSWR3_RX_8 | ZSWR3_RX_ENABLE,
  70         ZSWR4_CLK_X16 | ZSWR4_ONESB | ZSWR4_EVENP,
  71         ZSWR5_TX_8 | ZSWR5_TX_ENABLE,
  72         0,      /* 6: TXSYNC/SYNCLO */
  73         0,      /* 7: RXSYNC/SYNCHI */
  74         0,      /* 8: alias for data port */
  75         ZSWR9_MASTER_IE,
  76         0,      /*10: Misc. TX/RX control bits */
  77         ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD,
  78         ((PCLK/32)/38400)-2,    /*12: BAUDLO (default=38400) */
  79         0,                      /*13: BAUDHI (default=38400) */
  80         ZSWR14_BAUD_ENA,
  81         ZSWR15_BREAK_IE,
  82 };
  83
  84 /*
  85  * This replaces "zs_reset()" in the sparc driver.
  86  */
  87 static void
  88 zs_setparam(struct zs_chanstate *cs, int iena, int rate)
  89 {
  90         int s, tconst;
  91
  92         memcpy(cs->cs_preg, zs_kgdb_regs, 16);
  93
  94         if (iena) {
  95                 cs->cs_preg[1] = ZSWR1_RIE | ZSWR1_SIE;
  96         }
  97
  98         /* Initialize the speed, etc. */
  99         tconst = BPS_TO_TCONST(cs->cs_brg_clk, rate);
 100         cs->cs_preg[5] |= ZSWR5_DTR | ZSWR5_RTS;
 101         cs->cs_preg[12] = tconst;
 102         cs->cs_preg[13] = tconst >> 8;
 103
 104         s = splhigh();
 105         zs_loadchannelregs(cs);
 106         splx(s);
 107 }
 108
 109 #ifndef KGDB_DEVNAME
 110 #define KGDB_DEVNAME "scca"
 111 #endif
 112 char *zs_kgdb_devname = KGDB_DEVNAME;
 113 /*
 114  * Set up for kgdb; called at boot time before configuration.
 115  * KGDB interrupts will be enabled later when zs0 is configured.
 116  * Called after cninit(), so printf() etc. works.
 117  */
 118 void
 119 zs_kgdb_init(void)
 120 {
 121         extern const struct cdevsw zstty_cdevsw;
 122         struct zs_chanstate cs;
 123         volatile struct zschan *zc;
 124         int escc, escc_ch, obio, zs_offset;
 125         int channel = 0;
 126         u_int32_t reg[5];
 127         char name[16];
 128
 129         if ((escc_ch = OF_finddevice(zs_kgdb_devname)) == -1)
 130                 return;
 131
 132         memset(name, 0, sizeof(name));
 133         if (OF_getprop(escc_ch, "device_type", name, sizeof(name)) == -1)
 134                 return;
 135
 136         if (strcmp(name, "serial") != 0)
 137                 return;
 138
 139         memset(name, 0, sizeof(name));
 140         if (OF_getprop(escc_ch, "name", name, sizeof(name)) == -1)
 141                 return;
 142
 143         if (strcmp(name, "ch-b") == 0)
 144                 channel = 1;
 145
 146         if (OF_getprop(escc_ch, "reg", reg, sizeof(reg)) < 4)
 147                 return;
 148         zs_offset = reg[0];
 149
 150         escc = OF_parent(escc_ch);
 151         obio = OF_parent(escc);
 152
 153         if (OF_getprop(obio, "assigned-addresses", reg, sizeof(reg)) < 12)
 154                 return;
 155         zc = (struct zschan *)(reg[2] + zs_offset);
 156
 157         kgdb_dev = makedev(cdevsw_lookup_major(&zstty_cdevsw), channel);
 158
 159         printf("zs_kgdb_init: attaching tty%02d at %d baud\n",
 160                 channel, kgdb_rate);
 161
 162         /* Setup temporary chanstate. */
 163         memset((void *)&cs, 0, sizeof(cs));
 164         cs.cs_channel = channel;
 165         cs.cs_brg_clk = PCLK / 16;
 166         cs.cs_reg_csr  = &zc->zc_csr;
 167         cs.cs_reg_data = &zc->zc_data;
 168
 169         /* Now set parameters. (interrupts disabled) */
 170         zs_setparam(&cs, 0, kgdb_rate);
 171
 172         /* Store the getc/putc functions and arg. */
 173         kgdb_attach(zs_getc, zs_putc, __UNVOLATILE(zc));
 174 }
 175
 176 /*
 177  * This is a "hook" called by zstty_attach to allow the tty
 178  * to be "taken over" for exclusive use by kgdb.
 179  * Return non-zero if this is the kgdb port.
 180  *
 181  * Set the speed to kgdb_rate, CS8, etc.
 182  */
 183 int
 184 zs_check_kgdb(struct zs_chanstate *cs, int dev)
 185 {
 186
 187         if (dev != kgdb_dev)
 188                 return (0);
 189
 190         /*
 191          * Yes, this is port in use by kgdb.
 192          */
 193         cs->cs_private = NULL;
 194         cs->cs_ops = &zsops_kgdb;
 195
 196         /* Now set parameters. (interrupts enabled) */
 197         zs_setparam(cs, 1, kgdb_rate);
 198
 199         return (1);
 200 }
 201
 202 /*
 203  * KGDB framing character received: enter kernel debugger.  This probably
 204  * should time out after a few seconds to avoid hanging on spurious input.
 205  */
 206 static void
 207 zskgdb(struct zs_chanstate *cs)
 208 {
 209         int unit = minor(kgdb_dev);
 210
 211         printf("zstty%d: kgdb interrupt\n", unit);
 212         /* This will trap into the debugger. */
 213         kgdb_connect(1);
 214 }
 215
 216
 217 /****************************************************************
 218  * Interface to the lower layer (zscc)
 219  ****************************************************************/
 220
 221 static void zs_kgdb_rxint(struct zs_chanstate *);
 222 static void zs_kgdb_stint(struct zs_chanstate *, int);
 223 static void zs_kgdb_txint(struct zs_chanstate *);
 224 static void zs_kgdb_softint(struct zs_chanstate *);
 225
 226 int kgdb_input_lost;
 227
 228 static void
 229 zs_kgdb_rxint(struct zs_chanstate *cs)
 230 {
 231         register u_char c, rr1;
 232
 233         /*
 234          * First read the status, because reading the received char
 235          * destroys the status of this char.
 236          */
 237         rr1 = zs_read_reg(cs, 1);
 238         c = zs_read_data(cs);
 239
 240         if (rr1 & (ZSRR1_FE | ZSRR1_DO | ZSRR1_PE)) {
 241                 /* Clear the receive error. */
 242                 zs_write_csr(cs, ZSWR0_RESET_ERRORS);
 243         }
 244
 245         if (c == KGDB_START) {
 246                 zskgdb(cs);
 247         } else {
 248                 kgdb_input_lost++;
 249         }
 250 }
 251
 252 static void
 253 zs_kgdb_txint(register struct zs_chanstate *cs)
 254 {
 255         register int rr0;
 256
 257         rr0 = zs_read_csr(cs);
 258         zs_write_csr(cs, ZSWR0_RESET_TXINT);
 259 }
 260
 261 static void
 262 zs_kgdb_stint(register struct zs_chanstate *cs, int force)
 263 {
 264         register int rr0;
 265
 266         rr0 = zs_read_csr(cs);
 267         zs_write_csr(cs, ZSWR0_RESET_STATUS);
 268
 269         /*
 270          * Check here for console break, so that we can abort
 271          * even when interrupts are locking up the machine.
 272          */
 273         if (rr0 & ZSRR0_BREAK) {
 274                 zskgdb(cs);
 275         }
 276 }
 277
 278 static void
 279 zs_kgdb_softint(struct zs_chanstate *cs)
 280 {
 281         printf("zs_kgdb_softint?\n");
 282 }
 283
 284 struct zsops zsops_kgdb = {
 285         zs_kgdb_rxint,  /* receive char available */
 286         zs_kgdb_stint,  /* external/status */
 287         zs_kgdb_txint,  /* xmit buffer empty */
 288         zs_kgdb_softint,        /* process software interrupt */
 289 };